Management of the human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) pandemic is one of the biggest medical and clinical challenges, in both developed and developing countries. Globally, over 40 million people are now living with HIV. In the management of HIV-infected subjects, absolute counts of CD4+ T cells per micro-liter of blood have been proven to be an essential biological indicator for HIV staging and treatment decisions. The immune system needs CD4 cells to function properly. The more CD4 cells in circulation, the stronger the immune system. Clinically, a CD4 count below 200 cells per micro-liter of blood establishes the diagnosis of AIDS.
Currently, the gold standard for CD4 counting is through flow cytometry. High throughput flow cytometry may not be applicable in resource-poor settings due to its demanding technical requirements and expensive costs. However, availability of portable, cheap CD4 counting using advanced technologies would increase the efficiency and accessibility of CD4 monitoring, and produce a tremendous clinical impact via timely diagnosis of new AIDS patients.